Bleaching powder



EDWARD TI'IORNDIKE LADD AND EBEN CHILDS SPEIDEN, OF NIAGARA FALLS, NEVI YORK, ASSIGNORS TO ISCO CHEMICAL COMPANY, INC., OF NIAGARA FALLS, NEW

YORK, A. CORPORATION OF NEW YORK.

BLEAGHING POWDER.

Specification of Letters Patent.

Patented July 4t, 1922,

No Drawing. Original application filed March 5, 1921, Serial No. 449,901. Divided and this application filed February 7, 1922.

T 0 aZZ whom it may concern: 7

Be it known that we, EDWARD TrroRNniKn LADD and EBEN CHILns SrnIDnN, both citi- Zens of the United States, both residing at Niagara Falls, in the county of Niagara and State of New York, have invented certain new and useful Improvements in Bleaching Powders; and we do hereby declare the following to be a full, clear, and exact description of the invention, such as will enable others skilled in the art to which it appertains to make and use the same.

This invention relates to the bleaching powder well known in commerce as chloride of lime, and has for its object to provide a product which will be more efficient in use than those heretofore proposed.

With these and other objects in view the invention consists in the novel product more fully hereinafter disclosed and particularly pointed out in the claim.

This application is a division of my copending application, filed March 5, 1921, Serial Number 449901 and entitled Bleaching powder and process of making the same.

In order that the precise invention may be the more clearly understood, it is said It is well known that in preparing the ordinary bleaching powder, it is customary to hydrate quick lime containing calcium oxide, G O, thus producing what is commercially known as a lime hydrate which may contain magnesium hydrate and other impurities carried by the lime. This said lime hydrate is next screened to separate therefrom the pieces of so called lime stone or so called core of the lime lumps, as well as to separate out such other foreign or undesirable impurities as may be susceptible of being' separated out by screening. The so called lime hydrate thus separated will be found to contain relatively coarse and fine particles, and the mass is next treated with chlorine in bleach chambers in the manner well known, so the chloride of lime or bleaching powder of commerce results.

According to this invention, on the other hand, we have observed that the lime hydrate together with such impurities as have not been separated out by the above mentioned process of screening may be divided into a portion containing the relatively coarse and into aportion containing Serial No. 534,764.

the relatively fine particles. We have also observed that if one separates out from the lime hydrate material substantially all, or a large percentage of the line particles of hydrate and impurities present, leaving behind in a second portion a large percentage of, or substantially all the coarse particles, and then treat said second portion of hydrate material with chlorine gas in the manner well known, a very different and useful product will result from that heretofore obtained. That is to say, the product of said treatment will be found to be heavier and more massive bleach than would be the case if said finer particles had not been removed.

In other words, it is probable the larger percentage of coarser particles now remaining in said second portion of the lime hydrate mass before chlorination, changes the character or size of the pores, or interstices, existing between the particles of the hydrated lime and therefore permits a more thorough penetration of the mass by the chlorine than is possible in the prior processes, with the result that a better or more eflicient chlorination results, and thus produces a corresponding change in the properties of the finished product. In the same way, we have further discovered that after removing all, or a substantial percentage of the coarse particles to form said other portion of hydrate containing all or a substantial percentage of the finer particles present if one treats this said other portion with chlorine gas, a bleach powder will be obtained which is lighter and more flufly than is the case when said coarser particles are left in the chlorinated mass. This change in the physical character of the last mentioned.

product is also probably due to the change may vary the details of the procedure as Well hydrate from which, before chlorination, a 10 as the products resulting from said procedsubstantial proportion of its smaller sized ures, Without departing from the spirit-of naturally occurring particles had been furthe invention, and therefore, We do not detherremoved, substantially'as described.

5 sire to be limited to the above disclosure, ex- In testimony whereof We aflix our signaeept as may be required by the claim. tures.

What we claim is V V The herein described new bleaching poW- EDWARD THORNDIKE LADD,

der consisting of a screened chlorinated lime EBEN CHILDS SPEIDEN. 

